What component can cause engine stalling if it malfunctions during a cold start?

The choke is a critical component during a cold start of an engine because its primary function is to restrict airflow into the carburetor. This restriction enriches the air-fuel mixture, which is essential for starting a cold engine since cold temperatures can make fuel less volatile, making it harder for the engine to ignite and run smoothly. When the choke is functioning correctly, it allows for a richer mixture that compensates for the low temperature, thereby preventing stalling.

If the choke malfunctions, it may either not engage properly or fail to close enough, resulting in a leaner mixture that can lead to poor starting, rough idling, and ultimately stalling as the engine is unable to maintain the necessary combustion conditions. Therefore, the choke's role in controlling the air-fuel mixture during cold starts makes it a critical component in preventing engine stalling.